Different User Agents in the browsers

I have noticed that some browsers via a build in development feature allow you to choose different user agents.

Does this mean that they change their rendering engine?

Say for example, if I set Safari's user agent to internet explorer - will that then change the rending engine from webkit to trident?

At the moment on my mac I have Safari, Chrome, Firefox and iCab installed. I would imagine they would represent the different engine's better than the user agent funct开发者_Go百科ion built in. However you are only limited to installing 1 version of each unless you go the virtual machine or dual boot way.

So what is your advice? Run multiple virtual machine and of course the extra licenses to do it legal will need to be purchased. or stick with the user agent function built in and that gives a good enough interperatation of the differences??

Cheers Jeff

Say for example, if I set Safari's user agent to internet explorer - will that then change the rending engine from webkit to trident?

No. A user agent is just a string that the browser sends to identify itself. I could set my user agent to cheeseburger if I wanted. It won't use a cheeseburger to try and render the page.

Officially, the only correct way to run Internet Explorer is on Windows - which would require a Windows installation - a VM is a perfect valid and common solution. On a Mac you also have the option of Bootcamp.

There are other services, like http://browsershots.org/, that allow you to specify a URL and they will send you a screenshot of what the URL likes like in a particular browser. I typically don't like these solutions because they are slow, you don't have any debugging tools, etc.

the user agent setting in safari (and other browsers) only spoofs the user agent, it doesn't change the rendering engine. you can use that spoofing, to get for example the iPhone version of a webpage in your desktop safari. to check your page in different browsers, you could use some web service like http://browsershots.org/ (thats just the first google result) or setup an array of virtual machines. we do the latter, which ineed costs you 2-3 windows licenses, but you can pack a lot of browsers into one virtual machine, just distribute the different versions among different machines